Single-fire-box kiln



May. 1o, 1927.

w. E. wlLsoN ET AL SINGLE FIREBOX KILN Filed Feb] 25. 1921 s sham-'sheeta Patented May 10, 1927.

UNITED STATES 1,627,720 PATENT OFFICE..

WILLIAM E. WILSON, OF MASON CITY, IOWA, AND HENRY Gr. LYKKEN, OF MINNE-APOLIS, MINNESOTA.

SINGLE-FIRE-BOX KILN.

Application filed February 25, 1921. Serial No. 447,661.

Our invention relates primarily to improvements in kiln constructionadapted for the use of various kinds of fuel and to reduce the amount offuel consumption.

I Among the objects of our invention are: to so construct a kiln for theburning of brick, tile, pottery etc. as to effect a maximum reduction inthe amount of fuel consumed; to construct a kiln adapted for the use ofvarious fuels such as fuel oil, fuel gas and powdered fuel; to soconstruct a. kiln as to secure regulated heat distribution throughoutthe ware being fired; to regulate the heat distribution; and suchfurther objects, advantages and capabilities as will later more fullyappear.

Ourv invention further resides in the combination, construction andarrangement of parts illustrated in the accompanying drawings, and whilewe have shown therein preferred embodiments, we desire the saine to beunderstood as illustrative only and not as limiting our invention.

In the present method of firing, there is a large heat loss due to thegreat amount of excess air carried in thru and over the multiplicity ofgrates and fires. of heat energy thru the heating of excess air to thehigh temperatures at which the ware is fired is the largest loss infiring prior types of kilns and there is no practical means of keepingsuch losses down to a reasonable minimum. By the use of one fire or atthe most two or three fires in a larger kiln these losses can be reducedin proportion to the reduction of the number of fires, particularly asit is possible, as in this invention, to utilize a better type of firebox in which it is possible to regulate more accurately the proportionof air used in firing.

A second large loss in the firing of the prior types of kiln is the factthat they have a limited combustion space. The burning of any fuelrequires not only a correct proportion of air supply, but an intimatemixture of the air supply with the gases distilled off from the burningfuel together with a large enough combustion space, giving time for suchmixing and time to burn. A large combustion chamber is not onlydesirable but necessary for the economical burning of all fuels, coaland other combustibles burned on a grate, as well as oil, gas andpowdered fuels. This invention provides such a com- This loss bustionchamber which can be made of any required dimensions.

In the'burning of gases, oil and powdered rfuel an intensely hot flameis produced which necessitates a large combustion chainn ber forcomplete combustion, in order that the gases may expand to obviate theerosive eeet of the high velocity gases of the flame itself, which Wouldbe destructive if impin'ged on the refractory of the kiln or the ware tobe burned. In this invention such a combustion chamber is provided whichcan be made of any suitable dimensions, which would obviously beimpossible with eight or more circumferential fires used with thepresent kiln.

By taking the products of combustion and gases direct from thecombustion chamber, when they are at their hottest, up thru the centerof the ware in the kiln, distributing it radially outward and downward,a better distribution of heat is obtained as the ware body heats fromthe inside radially outwards while the descending gases may be deflectedand pulled ldown along the circumferential walls.

It is also obvious that in this construction an increased capacity ofthe kiln is obtained in that the ascending central flue or opening leftin the mass of the ware to be burned occupies less of the volume of thekiln than the multiplicity of fire bags required in the prior forms ofkiln. This kiln also permits of a less expensive wall construction,which may be reduced considerably in'thickness if properly insulated. Itreduces tremendously the amount of `high refractory material required,in that the impinging flame and radial heat is confined in the onecombustion chamber and strikes the kiln proper only at the apex of thedome eliminating any necessity of high refractory in the wallvconstruction of the kiln proper.

In the drawings annexed hereto and forming a part hereof, Figs. l, 2 and3 are vertical sections showing the application of various modes ofheating a kiln in accordance with our invent-ion; Fig. 4: is a verticaltransverse section of a kiln such as that shown in Fig. 6; Fig. 5 is ahorizontal section of a kiln embracing our invention; Fig. 6 is asimilar section of another form of draft control means, comprised in ourinvention; Fig. 7 is a still further modification showing an arrangementfor firing two kilns from one tire box; Figs. 8 and 9 show respectivelya plan view and a vertical longitudinal section of another form of ourinvention, in which the lire box runs on a track over the kilns and thefire is-directed downwardly through the top thereof; Fig. lO is asomewhat similar modification in which the tire box runs .on a track ator near ground level and may tire either a kiln the right or at l'thelett desired; and Fig. l1. is a Vfurther modification in which a lirebox is `loca-ted .centrally o' a ring ol kilns and vdirects the heat andproducts ot combustion laterally into any one et the kilns as desired.

Referring more in .detail to the annexed drawings numeral l indicatesthe kiln wall, :provided with lieat insulating material 2, to reduceVthe amount of heat radiated laterally .through .the kiln walls. 3-denotes the oil, priwdered lcoal, or ,lump :tuelsuch as coal and lhelike. This lire box may .open into the kiln centrally as is shown inFigs. l, L). and 3,01' at one side ot the kiln, through a structuresimilar' to a bag tire box.

ln Figures l, 2 and 3 the tlue or stack (l is shown as a .pe'rinaiunt.part of the structure, while in llig. 4L vthis is omitted, the ware vtobe burned being stacked so as to torni a central tlue tor the upwardpassage ot' the heat aud `rases result-ing from the combastion of thefuel. The heat passing upwardly through vthe flue, whether this becentrally arranged -or arranged at one side ot the kiln, strikes .thedome 3 and then passes downwardly through the ware and out tl'irough thelioor through the outlet openings 7, from which .escape is by Way otducts 7a. Only so much of the dome is lined with refractory material asis necessary .to resist .the action of the directly iinpinging heat,rentering thru the flue 6, thus reducing to a minimum .the yamount olrefractory material required. Surrounding the wall l and communicatingwith ducts 7 ,is a .duct .8, which may be shut .olf from one or more ,otthe .ducts 7a by `dampers 9. lt should be noted .that the duct 8 .may belocated inside ot the wall l, itv `desired or considered necessary, andmay .communicate with the ducts v7'?. It is, however, consideredpreferable to have the `duct 8 outside ot the wall 1. There `are someinstances in which it is practically impossible to arrange the dra'ltducts 7 as shown in Fig. G, owing to the tact Athat in a kiln alreadybuilt it would be hard to cut so many openings through the kiln walls.In such a case the ducts or {lue-s may be arranged as shown in Fig. 5,in which case only a single opening,

box serves to VAtire either ot two kilns, or, il

desired, both ot them simultaneoilsly. Connected with the lire box is aduct or exhaust pipe l2 which leads into a main exhaust ful pipe 13,Aconnected with the stack or .exhaust tan, so that, when desired, .thedirection ot the air through the kiln can be reversed.

Figs. 8 and 9 show the application ot a single lire box traveling on a'track above the top of a row ot kilns, so that the tire can be appliedto the top ot a'kiln and the heat and products ot combustion drawn outthrough the bottom thereof. .in .this instance av track l is erectedabove the row ot kilns and carries a lire box l5, which is preferablytired with oil, powdered coal, vor

the like, 'for the production of the heat. ln 1Eig. 9 is shown a torceleed means 16 drawing tuel trom a tank i7, and blowing the same into thetire box 'l5 where it burned. In this construction the exhaust pipes arenot shown.

In Fig. l() the ducts leading troni :the lire box l to the middle of thekilns are placed below the level of the ground and the heat passes fromthe tire box l5 to the right or left as desired, or may be used to lire.two kilns at once it' so desired. Here also the exhaust ducts areomitted tor the sake of clearness.

In Fig. ll a plurality of kilns are set in a circle around a central pitin which is located. a pivotally mounted blower, which may be turned todirect .the lire into anyone of the lire boxes 5, from which the heatwill rise through the center .opening of the kiln as in Fig. l, villstrike the dome ot the kiln, and then be deflected downwardly to and`through the ware, traveling outwardly through ducts 8, l0 and ll to thestack or fan 18.

It is of course understood that the specilic description ot structureand method set forth above may be departed from without departing tronithe spirit oit .our invention as set forth in this specilication and theappended claims.

Having now described our invention, we claim:

l, In a kiln having a root and a floor, a

single lire box beneath the floor, saidV tloor having an apertiueconnecting the lire box with the interior ot' the kiln and a pluralityot apertures surrounding the first named aperture and communicating withthe interior ol the kiln, a plurality ot' passage- Ways beneath the Hoorof the kiln With which the apertures in said floor communicate, and acommon duct Communicating With all of said passageways and connectedwith an exhaust duct so that the Waste products of Combustion may beWithdrawn through the floor of the kiln.

2. That step in the method of burning plastic Ware which comprisesstacking a portion of the Ware around an opening 10 v*che top thereof.

In witness whereof, We hereunto sub- 15 scribe our names to thisspecification.

WM. E. WILSON. HENRY Gr. LYKKEN.

